" Federal authorities warned Antifa members Monday to stop occupying an Oregon Immigration and Customs Enforcement (ICE) building or be arrested.

“Individuals who continue to obstruct the entrance of this federal facility will be subject to arrest and prosecution in federal court,” a flyer Federal Protective Service agents distributed to Portland, Oregon, Antifa members reads. “It is unlawful under federal law to obstruct the entrances, foyers, lobbies, corridors, offices and/or parking lots of federal facilities.”

Antifa has been camping outside the ICE building since last week and effectively shutting down the building. Federal authorities went into the building around 3:30 a.m Monday to secure the building.

Antifa is known to get violent and they are labeled an official domestic terrorist organization. "